How to make a looping BGM with an intro (and also have an audio visualizer)

I know it sounds trivial, but it’s surprisingly hard to find a tutorial that explains how to do something simple like this with the new audio engine.
As the title says, I don’t want any fancy interactive music, but just a normal BGM track that loops and has an intro which plays once before the first loop.
Well, I guess it’s a bit fancy in that I also want a little audio visualizer as part of the HUD for which up until now I’ve been using Calculate Frequency Spectrum.
I’ve tried using a normal sound cue which concatenates the Intro and the Loop wave, with the Loop wave being set to loop, but A) this has a small pause between the Intro and the Loop and B) Calculate Frequency Spectrum doesn’t accept a sound cues, only sound waves.
Is there some functionality in the new audio engine that can easily achieve this? Because from what I’ve seen, having to learn TimeSynth seems a bit overkill for one single concatenation.


Check this thread out for audio visualizer work @ArthurBarthur is doing. Very good stuff here.